This section is intended to introduce the reader to various aspects of art that may be related to various aspects of the presently described embodiments. This discussion is believed to be helpful in providing the reader with background information to facilitate a better understanding of the various aspects of the described embodiments. Accordingly, it should be understood that these statements are to be read in this light and not as admissions of prior art.
Blowout preventers (“BOPs”) are used to prevent blowouts during the drilling and production of oil and gas wells. BOPs are installed at the wellhead for the purpose of reducing the likelihood of an undesired escape of fluid from an annular space between the casing and drill pipe or from an open hole during drilling and completion operations.
BOPs are large, high-pressure valves capable of being remotely controlled. There are two basic types of BOPs, an annular-type BOP and a ram-type BOP. On floating offshore rigs, such as semisubmersibles and drill ships, BOPs may also be attached to the well on the seafloor. In such subsea applications, a plurality of BOPs may also be stacked on top of one another and referred to as a BOP stack.
A well control system monitors and controls the subsea BOPs from the drilling rig and one of the components of the system is a subsea control pod. The subsea control pod actuates and controls the subsea BOP stack with hydraulic fluid either from the drilling vessel or subsea actuators. The subsea control pods contain pilot operated control valves and pilot operated regulators which control flow of the hydraulic fluid to the various BOP hydraulic operators controlling the BOP functions.
When activating a BOP using a subsea control pod, pressurized hydraulic fluid is provided to the BOP through the valves and passages of the subsea control pods. Due to the high pressures of the hydraulic fluid, a pressure surge or wave caused from suddenly starting or stopping fluid flow, commonly referred to as fluid hammer or hydraulic shock, may reduce the life expectancy of the valves, hoses, and/or other components of the subsea control pods or other subsea equipment. Accordingly, reducing the effects of a fluid hammer, for example, will help to increase the life expectancy of subsea components, particularly in these remote locations where maintenance may be difficult.